The present invention relates to safety critical control systems. In particular, the invention relates to software and hardware systems and methods that implement a control system for systems that require high reliability and safety.
A life-critical system or safety-critical system is a system whose failure or malfunction may result in death or serious injury to people; loss or severe damage to equipment and/or environmental harm. A variety of approaches have been attempted to increase safety margins and reliability however these approaches have resulted in a variety of disadvantages which result in undesirable first, second, and third order effects.
For example, single signal systems result in a susceptibility to stray voltage activated control inputs and serial control systems result in increased overhead and complexity which can create different failure modes. Increased overhead requires more complex software and control systems such as advanced microprocessors that have to be ruggedized against a variety of environmental threats. Complex software requires substantial resources including time and personnel to write and maintain. Therefore, improvements to existing state of the art control systems are needed to enable use of safety critical control systems in environments where high reliability and simplified implementation are required.